Many enzymes consist of a protein and a non-protein (called the cofactor). The proteins in enzymes are usually globular. The intra- and intermolecular bonds that hold proteins in their secondary and tertiary structures are disrupted by changes in temperature and pH. This affects shapes and so the catalytic activity of an enzyme is pH and temperature sensitive.
Everyday in the U.S. millions of cars and trucks idle needlessly, sometimes for hours. You may not be able to avoid keeping your engine running when youâre stopped at a traffic signal or stuck in slow-moving traffic. But other times idling is unnecessary. An idling car can release as much pollution as a moving car.
Idling in winter thus has no benefit to your (presumably modern) car. Auto experts today say that you should warm up the car no more than 30 seconds before you start driving in winter. The engine will warm up faster being driven, the EPA and DOE explain. Indeed, it is better to turn your engine off and start it again than to leave it idling.